Microtomes are used to cut thin sections from samples. These sections are subsequently placed on a coverslip, suitably processed, and then examined under a microscope.
Microtomes are used to cut thin sections from samples. These sections are subsequently placed on a coverslip, suitably processed, and then examined under a microscope.
In known rotary microtomes, the cutting unit is driven by turning at least one hand wheel. There are users who find it more comfortable to turn the first hand wheel clockwise, while other users find it comfortable to turn the first hand wheel counterclockwise. Therefore, there are commercially available microtomes in which the hand wheel has to be rotated clockwise, as well as microtomes in which the hand wheel has to be rotated counterclockwise. The user must choose one of the two variants at the time of purchase. The direction of rotation can later be changed only by a technician making extensive and complex modifications to the microtome.
US2008/0000339 describes a crank drive system of a shaft of a microtome. This crank drive system has the problem that in order to change the direction of rotation, the second shaft has to be moved axially together with the transfer means mounted thereon. It is also problematic that the crank drive system is complex and requires a considerable amount of space.
US2012/0060664 discloses a microtome having means for reversing a direction of rotation. The microtome comprises a first shaft which is arranged in a fixed position and capable of being driven by a hand wheel and which has a first gear wheel non-rotatably mounted thereon. The microtome further includes a second shaft which is arranged in a fixed position and has a second gear wheel mounted thereon. The first gear wheel and the second gear wheel are coupled to each other via a transmission unit, so that the second shaft can be driven by the first shaft. In a first position of the transmission unit, the two shafts are rotatable in the same direction, while in a second position of the transmission unit, they are rotatable in opposite directions. The disadvantage of the prior art is that it requires at least three idler gears for the transmission unit. This increases the complexity of the transmission unit, and requires more parts thereby increasing costs.